• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.2 no.2
• /
• pp.96-102
• /
• 2016

Apoptosis, a genetically determined process of programmed cell death, is considered a vital component of various processes including normal cell turnover, animal development, and tissue homeostasis. It has a crucial role in many medical disorders and hence the development of non-invasive imaging tool is highly demanded. Recently, we have developed a peptide-based radioactive probe (ApoPep-1) for apoptosis detection. In that work the potential of probe for apoptosis detection was verified, however in vivo stability of radiolabeled peptide was not enough to monitor apoptosis for extended period. In current study, we prepared cyclic ApoPep-1 peptides to improve the stability of origianl linear ApoPep-1 and carried out direct comparison studies in vitro and in vivo. A targeting efficacy of newly synthesized cyclic ApoPep-1 peptide for apoptosis was confirmed in acute myocardial infarct model.

• Journal of Environmental Science International
• /
• v.13 no.4
• /
• pp.403-412
• /
• 2004

Waste water-soluble cutting oil was treated with WI type #1 and WI type #2. The properties of the original water-soluble cutting oil were pH=l0.4, viscosity=1.4cP, CODcr=44,750 ppm, and TOC=10,569 ppm. However, the properties of the oil used for more than 3 months were changed to pH=7.82, viscosity=2.1cP, CODcr=151,000 ppm, and TOC=74,556 ppm. It might be attributed to the fact that molecular chains were cut due to thermal oxidation and impurities such as metal chips were incorporated in to the oil during the operation processes. To prevent the putrefaction of oil, the sterilization effect of ozone and UV on the microorganism in the oil was investigated. Ozone treatment showed that 99.99% of the microorganism was annihilated with 30 minutes contact time and 60 minutes were necessary for the same effect when UV was used. Ozone treatment could cut molecular chains of the oil due to strong sterilization power, which was evidenced by the increase of TOC from 25,132 ppm at instantaneous contact to 28,888 ppm at 30 minutes contact time. However, UV treatment didn't show severe changes in TOC values and thus, seemed to cause of severe cut of molecular chains. When the activated carbon was used to treat the waste water-soluble cutting oil, TOC decreased to 25,417 ppm with 0.lg carbon and to 15,946 ppm with 5.0g carbon. This results indicated that the waste oil of small molecular chains could be eliminated by adsorption. From the results, it could be concluded that these treatment techniques could be proposed to remove the waste oil of small molecular chains resulting in the degradation of the oil properties. In addition, these experimental results could be used for the correlation with future works such as investigation of the molecular distribution according to the sizes, lengths, and molecular weight of the chains.

• Genomics & Informatics
• /
• v.2 no.2
• /
• pp.67-74
• /
• 2004

Cells consistently face stressful conditions, which cause them to modulate a variety of intracellular processes and adapt to these environmental changes via regulation of gene expression. Hyperosmotic and oxidative stresses are significant stressors that induce cellular damage, and finally cell death. In this study, oligonucleotide microarrays were employed to investigate mRNA level changes in cells exposed to hyperosmotic or oxidative conditions. In addition, since heat shock protein 70 (HSP70) is one of the most inducible stress proteins and plays pivotal role to protect cells against stressful condition, we performed microarray analysis in HSP70-overexpressing cells to identify the genes expressed in a HSP70-dependent manner. Under hyperosmotic or oxidative stress conditions, a variety of genes showed altered expression. Down­regulation of protein phosphatase1 beta (PP1 beta) and sphingosine-1-phosphate phosphatase 1 (SPPase1) was detected in both stress conditions. Microarray analysis of HSP70-overexpressing cells demonstrated that diverse mRNA species depend on the level of cellular HSP70. Genes encoding Iysyl oxidase, thrombospondin 1, and procollagen displayed altered expression in all tested conditions. The results of this study will be useful to construct networks of stress response genes.

• The Bulletin of The Korean Astronomical Society
• /
• v.46 no.1
• /
• pp.50.2-51
• /
• 2021

Stars form exclusively in cold and dense molecular clouds. To fully understand star formation processes, it is hence a key to investigate how molecular clouds form out of the surrounding diffuse atomic gas. With an aim of shedding light in the process of the atomic-to-molecular transition in the interstellar medium, we analyze Arecibo HI emission and absorption spectral pairs along with TRAO/PMO 12CO(1-0) emission spectra toward 58 lines of sight probing in and around molecular clouds in the solar neighborhood, i.e., Perseus, Taurus, and California. 12CO(1-0) is detected from 19 out of 58 lines of sight, and we report the physical properties of HI (e.g., central velocity, spin temperature, and column density) in the vicinity of CO. Our preliminary results show that the velocity difference between the cold HI (Cold Neutral Medium or CNM) and CO (median ~ 0.7 km/s) is on average more than a factor of two smaller than the velocity difference between the warm HI (Warm Neutral Medium or WNM) and CO (median ~ 1.7 km/s). In addition, we find that the CNM tends to become colder (median spin temperature ~ 43 K) and abundant (median CNM fraction ~ 0.55) as it gets closer to CO. These results hints at the evolution of the CNM in the vicinity of CO, implying a close association between the CNM and molecular gas. Finally, in order to examine the role of HI in the formation of molecular gas, we compare the observed CNM properties to the theoretical model by Bialy & Sternberg (2016), where the HI column density for the HI-to-H2 transition point is predicted as a function of density, metallicity, and UV radiation field. Our comparison shows that while the model reproduces the observations reasonably well on average, the observed CNM components with high column densities are much denser than the model prediction. Several sources of this discrepancy, e.g., missing physical and chemical ingredients in the model such as the multi-phase ISM, non-equilibrium chemistry, and turbulence, will be discussed.

• Molecular Medicine Reports
• /
• v.20 no.3
• /
• pp.2339-2346
• /
• 2019

Reactive oxygen species (ROS) are important cellular second messengers involved in various aspects of cell signaling. ROS are elevated in multiple types of cancer cells, and this elevation is known to be involved in pathological processes of cancer. Although high levels of ROS exert cytotoxic effects on cancer cells, low levels of ROS stimulate cell proliferation and survival by inducing several pro-survival signaling pathways. In addition, ROS have been shown to induce epithelial-mesenchymal transition (EMT), which is essential for the initiation of metastasis. However, the precise mechanism of ROS-induced EMT remains to be elucidated. In the present study, it was indicated that ROS induce EMT by activating Snail expression, which then represses E- cadherin expression in MCF-7 cells. It was further indicated that distal-less homeobox-2 (Dlx-2), one of the human Dlx gene family proteins involved in embryonic development, acts as an upstream regulator of ROS-induced Snail expression. It was also revealed that ROS treatment induces the glycolytic switch, a phenomenon whereby cancer cells primarily rely on glycolysis instead of mitochondrial oxidative phosphorylation for ATP production, even in the presence of oxygen. In addition, ROS inhibited oxidative phosphorylation and caused cytochrome c oxidase inhibition via the Dlx-2/Snail cascade. These results suggest that ROS induce EMT, the glycolytic switch and mitochondrial repression by activating the Dlx-2/Snail axis, thereby playing crucial roles in MCF-7 cancer cell progression.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.6
• /
• pp.616-621
• /
• 2008

Osseointegration is a result of bone formation and bone regeneration processes, which takes place at the interface between bone and implant, and it indicates a rigid fixation that can be stably maintained while functional loading is applied inside the oral cavity as well as after implant placement. Although many researches were carried out about osseointegration mechanism, but cellular and molecular events have not been clarified. With recent development of molecular biology, some researches have examined biological determinants, such as cytokine, growth factors, bone matrix proteins, during osseointegration between bone and implant surface, other researches attempted to study the ways to increase bone formation by adhering protein to implant surface or by inserting growth factors during implant placement. Cellular research on the reaction of osteoblast especially to surface morphology (e.g. increased roughness) has been carried out and found that the surface roughness of titanium implant affects the growth of osteoblast, cytokine formation and mineralization. While molecular biological research in dental implant is burgeoning. Yet, its results are insignificant. We have been studying the roles of growth factors during osseointegration, comparing different manifestations of growth factors by studying the effect of osseointegration that varied by implant surface. Of many growth factors, $TGF-{\beta}$, IGF-I, BMP2, and BMP4, which plays a significant role in bone formation, were selected, and examined if these growth factors are manifested during osseointegration. The purpose of this article is to present result of our researches and encourage molecular researches in dental implant.

• Proceedings of the Botanical Society of Korea Conference
• /
• 1995.07a
• /
• pp.57-86
• /
• 1995

Molecular mapping of plant genomes has progressed rapidly since Bostein et al.(1980) introduced the idea of constructing linkage maps of human genome based on restriction fragment length polymorphism (RFLP) markers. In recent years, the development of protein and DNA markers has stimulated interest for the new approaches to plant improvement. While classical maps based on morphological mutant markers have provided important insights into the plant genetics and cytology, the molecular maps based on molecular markers have a number of inherent advatages over classical genetic maps for the applications in genetic studies and/or breeding schemes. Isozymes and DNA markers are numerous, discrete, non-deleterious, codominant, and almost entirely free of environmental and epistatic interactions. For these reasons, they are widely used in constructing detailed linkage maps in a number of plant species. Plant breeders improve crops by selecting plants with desirable phenotypes. However a plant's phenotyes is often under genetic control, positioning at different "quantitative trait loci" (QTLs) together with environmental effects. Molecular maps provide a possible way to determine the effect of the individual gene that combines to produce a quantitative trait because the segregation of a large number of markers can be followed in a single genetic cross. Using market-assisted selection, plants that contain several favorable genes for the trait and do not contain unfavourable segments can be obtained during early breeding processes. Providing molecular maps are available, valuable data relevant to the taxonomic relationships and chromosome evolution can be accumulated by comparative mapping and also the structural relationships between linkage map and physical map can be identified by cDNA sequencing. After constructing high density maps, it will be possible to clone genes, whose products are unknown, such as semidwarf and disease resistance genes. However, much attention has to be paid to level-up the basic knowledge of genetics, physiology, biochemistry, plant pathology, entomology, microbiology, and so on. It must also be kept in mind that scientists in various fields will have to make another take off by intensive cooperation together for early integration and utilization of these newly emerging high-techs in practical breeding. breeding.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.300-300
• /
• 2006

Nondestructive nanostructural analysis is indispensable in the development of nano-materials and nano-fabrication processes for use in nanotechnology applications. In this paper, we demonstrate for the first time a quantitative, nondestructive analysis of nanostructured thin films supported on substrates and their templated nanopores by using grazing incidence X-ray scattering and data analysis with a derived scattering theory. Our analysis disclosed that vertically oriented nanodomain cylinders had formed in 20-100 nm thick films supported on substrates consisting of a mixture of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and PMMA homopolymer, and that the PMMA nanodomains were selectively etched out by ultraviolet light exposure and a subsequent rinse with acetic acid, resulting in a structure consisting of hexagonally packed cylindrical nanopores.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.41.1-41.1
• /
• 2012

Interactions between the galactic interstellar medium (ISM) and the intra cluster medium (ICM) are believed to be one of the main processes affecting galaxy evolution in cluster environments. The aim of our research is to study the molecular gas properties of a galaxy under the ICM pressure in the cluster environment. It has been well known that cluster galaxies are deficient in atomic hydrogen gas (HI gas) compared to their field counterparts and now there is much evidence that low density ISM is being removed by ram pressure due to ICM wind. Meanwhile, no significant molecular gas deficiency of the cluster galaxy population has been found yet they show overall lower star formation rate than galaxies in the field, and it is still puzzling how the star formation could decrease without stripping of dense molecular gas. To address this issue, we probe the detailed molecular gas properties of NGC 4402, located near the cluster center, as part of a study of four spiral galaxies in the Virgo Cluster. NGC 4402 is well known undergoing ram pressure stripping with a truncated HI disk($D_{HI}/D_{opt}$ - 0.75 and only 36% of HI gas compare to field galaxies of a similar size) and a disturbed gas morphology. Comparing the high resolution 12CO and 13CO data of NGC 4402 from the Sub Millimeter Array (SMA) with existing other wavelength data, we probe the spatial distribution and a physical condition of molecular gas under strong ICM pressure. We discuss the star formation activity might have been altered and hence how the global color of NGC4402 would change in the future.

• BMB Reports
• /
• v.40 no.3
• /
• pp.349-357
• /
• 2007

The ubiquitous family of 14-3-3 proteins functions as regulators in a variety of physiological processes. Eight rice 14-3-3 genes, designated OsGF14a through h, were identified from an exhaustive search of the genome database. Comparisons of deduced amino acid sequences reveal a high degree of identity among members of the OsGF14 family and reported Arabidopsis 14-3-3 proteins. A phylogenetic study indicates that OsGF14s contain both $\varepsilon$ and non-$\varepsilon$ forms, which is also confirmed by a structural analysis of OsGF14 genes. Furthermore, transcripts of OsGF14b, OsGF14c, OsGF14d, OsGF14e, OsGF14f and OsGF14g were detected in rice tissues. Their different expression patterns, the different effects of environmental stresses and plant hormones on their transcription levels, and the different complementary phenotypes in yeast 14-3-3 mutants not only indicates that OsGF14s are responsive to various stress conditions and regulated by multiple signaling pathways, but also suggests that functional similarity and diversity coexist among the members of OsGF14 family.